1. Field of the Invention
The present invention relates to a high molecular weight antitumor antibiotic which has a broad antitumor activity against the cells of mouse leukemia and which exhibit very low toxicity.
2. Description of the Prior Art
Many high molecular weight peptides produced by members of the group Actinomycetes have been known to exhibit antibiotic activity. Among known agents, high molecular weight antibiotics which exhibit antimicrobial activity are shown in Table 1.
TABLE 1 ______________________________________ Known High Molecular Weight Antibiotics Name Reference ______________________________________ Carcinocidin Y. Harada, T. Nara and F. Okamoto: J. Antibiotics, serA 9(1), 6(1956). Melanomycin R. Sugawara, A. Matsunae and T. Hata: J. Antibiotics, serA 10(4), 133(1956). A-280 Y. Sekizawa, S. Inouye and K. Kagino: J. Antibiotics, serA 15(6), 236(1962). Iyomycin complex S. Nomura, H. Yamamoto, A. Matsumae and T. Hata: J. Antibiotics, serA 17(3), 104(1964). Plurallin H. Ogawara, K. Maeda, K. Nitta, Y. Okami: J. Antibiotics, serA 19(1), 1(1966). Actinoxanthin Khokholv, A.S. et al: J. Antibiotics, 22, 541(1969). Neocarzinostatin Ishida, N., K. Mizazaki, K. Kumagai & M. Rikimaru: J. Antibiotics, serA 18(2), 68(1965). Macromomycin Chimura, H., M. Ishizuka, S. Hori, K. Kimura, J. Iwanaga, T. Takeuchi and H. Umezawa: J. Antibiotics, 21, 44(1968). Sporamycin Umeyawa H., K. Komiyama, H. Takesima, J. Awaga & S. Omura: J. Antibiotics, 29, 1249(1976). ______________________________________
Of these known antibiotics, Neocarzinostatin (hereinafter referred to as NCS) is a commercial product and is available on the market as a cancer chemotherapeutic agent. However, many of the remaining compounds are not of commercial importance because of their toxic properties and because of their comparatively low effectiveness. A need, therefore continues to exist for high molecular weight antibiotics which exhibit excellent activity while also exhibiting substantially reduced toxicity.